The pericranial flap is a reliable option for reconstructing the anterior skull base in extended endoscopic endonasal procedures when the nasoseptal flap is unavailable or insufficient. We describe a minimally invasive and fast technique for harvesting a vascularized pericranial flap using a three-dimensional exoscope through a small frontal incision, with simultaneous endoscopic endonasal placement, for anterior skull base reconstruction. Exoscope-assisted pericranial flap harvest provides excellent visualization, ergonomics, and flap control, enabling reliable orbit-to-orbit coverage of large anterior skull base defects with low donor-site morbidity when intranasal vascularized options are limited.

Candida meningitis is a rare but potentially deadly complication in neurosurgical patients. Most of the published case series include patients who underwent a craniotomy, while just three cases have been reported in patients operated on by transsphenoidal surgery. We performed an institutional review of patients who underwent transsphenoidal surgery over the last 5years (2020-2024) at Karolinska University Hospital, Stockholm, Sweden, and searched for patients who were also diagnosed with Candida meningitis as a postoperative complication. Out of over 400 operated patients, we identified three patients who were affected by postoperative candida meningitis. Two were male, (31 and 70years old), and one female (37years old). Pathological analyses revealed craniopharyngioma for the male patients and adenoma for the female patient. Postoperative CSF rhinorrhea occurred in all three patients, and they underwent endonasal endoscopic CSF leak repair surgery and were also treated with lumbar drainage. While none of them was previously immunocompromised, they all developed pituitary failure and were treated with hydrocortisone. The patients were successfully treated with Amphotericin B and Fluconazole. Although uncommon, Candida meningitis can occur in patients undergoing transsphenoidal surgery and should be suspected in cases of meningitis that do not respond to antibacterial drugs. Previous reports identified extremes of age and previous diagnosis of cancer and immunosuppression as risk factors while the three cases that we report here suggest that Candida meningitis can occur even in previously relatively healthy individuals. Other relevant risk factors for the development of Candida meningitis, such as large central tumors, postoperative CSF leakage, and prolonged cortisone use, should also be considered in the diagnostic process.

François Pourfour du Petit (1664-1741) is one of the most versatile scientists in medical history. Trained as a surgeon, chemist, ophthalmologist, and botanist, Petit was an intellectual who combined science with observation and experimentation. Through meticulous examination of the complex structure of the human nervous system, Petit provided important experimental observations on the decussation of the pyramidal tract and offered influential insights into the origin of the sympathetic nervous system. These discoveries directly influenced both the understanding of neurological injuries and the development of surgical interventions. His medical education began in 1687 as a student of Pierre Chirac at the Faculty of Medicine in Montpellier, culminating in his receiving the title of doctor in 1690. In Paris, at the Jardin Royal des Plantes, he studied under leading scientists of the time, including M. Duverney, M. de Tournefort, and M. Lémery, performing dissections and surgeries. While serving in Louis XIV's army, he observed neurological injuries in patients in military hospitals, providing revolutionary insights into the relationship between the nervous system and motor functions. Petit's meticulous measurements and experimental approach influenced not only brain anatomy but also eye anatomy and cataract surgery. While working as an ophthalmologist in Paris, he successfully performed cataract surgery on a woman in Fresnes in 1726, restoring her vision. Pourfour du Petit died after undergoing surgery for a long-standing recurrence of a hernia. He left behind not only his observations but also a methodological legacy aimed at understanding the structure of the human brain. His work remains a guiding light in the literature of neuroanatomy and brain surgery, ensuring that he is remembered as one of the pioneers of modern medicine.

Traumatic brain injury (TBI) patients are at risk of sudden deterioration, requiring timely diagnostics and treatment to prevent secondary cerebral injuries. This study investigated lead times in prehospital and early intrahospital TBI management, assessing their association with geographical conditions, hospital caseloads, and patient outcomes. This nationwide, observational cohort study included 5036 TBI patients (during 2018-2022) from the Swedish Trauma Registry (SweTrau). Lead times from trauma to alarm, from alarm to hospital arrival, and times to first computed tomography (CT) from alarm and hospital arrival, respectively, were calculated. These were analyzed against the geographical distribution of healthcare, hospital caseloads, and 30-day mortality. The majority of the cohort arrived in hospital within one hour and suffered a mild-to-moderate TBI. In univariate analyses, healthcare regions with larger geographical catchment areas exhibited longer time of prehospital management from alarm to arrival in hospital than smaller regions. Meanwhile, in multivariate linear regressions, larger region catchment area was independently associated with longer times from trauma to alarm and from alarm to hospital, but shorter time from alarm to first CT. In similar multivariate analyses, higher caseload was associated with longer time from alarm to first CT. Patients who were initially managed in a local hospital exhibited longer lead times overall, except from time to first CT from arrival in hospital. Furthermore, in the whole cohort, longer time from alarm to first CT and from arrival in hospital to first CT were associated with lower rate of mortality in univariate logistic regressions. However, this did not hold true in multivariate analysis after adjusting for demography and injury severity. Lead times in TBI management varied by both geographical and hospital-bound factors. Faster lead times in TBI were associated with higher mortality in univariate analysis, but this association disappeared in multivariate analysis, suggesting that clinical severity rather than time alone is the stronger predictor of outcome. Nonetheless, it remains believed that efficient and qualitative management is a fundamental necessity for better outcomes in TBI management.

Conventional unilateral biportal endoscopic discectomy for subarticular herniations frequently necessitates extensive hemilaminectomy, increasing the risks of iatrogenic instability and epidural scarring. The K-point approach is a precision docking technique utilizing the medial junction between the inferior and superior articular processes. By creating a strategic lateral corridor, it minimizes bone removal and exposes the lateral margin of the ligamentum flavum, allowing direct access to the traversing nerve root. By reducing bone resection and preserving the ligamentum flavum, the K-point approach enhances surgical efficiency and provides a refined minimally invasive alternative for subarticular disc herniations.

Accurate exposure of lesions on the medial cerebral hemisphere remains technically challenging, and current imaging cannot fully depict the subcortical intricate architecture extending from the medial surface outward. Although portions of this anatomy have been described, a comprehensive topographic characterization from medial to lateral is still lacking. To provide a systematic, layer-by-layer topographic analysis of the white-matter fiber tracts and deep gray-matter nuclei from the medial surface to the lateral convexity of the cerebral hemisphere by combining stepwise fiber dissection with three-dimensional (3D) photography. Twelve adult human cerebral hemispheres, fixed in 10% formalin and prepared with the Klingler fiber-dissection technique, were examined under 6× - 40 × magnification. Dissection commenced at the medial surface and proceeded outward, exposing commissural, association, and projection fibers as well as adjacent subcortical nuclei. High-resolution stereoscopic images were captured after each stage to document 3D spatial relationships. From medial to lateral, the hemisphere comprised orderly layers of commissural, association, and projection systems interwoven with deep nuclei, forming a complex but reproducible arrangement in all specimens. The study provides complete medial exposure of these structures and demonstrates consistent positional relationships among different specimens. This 3D fiber-dissection study offers the layer-by-layer depiction of the cerebral hemisphere from medial to lateral, clarifying spatial relationships among key white-matter bundles and deep nuclei. The anatomic insights gained may facilitate safer, more precise neurosurgical approaches and refine understanding of hemispheric connectivity.

Decompressive craniectomy and subsequent cranioplasty are associated with significant morbidity (Kurland et al. Neurocrit Care 23:292-304, 2015). Bone flap-preserving techniques, including floating and hinged craniotomies, offer effective intracranial pressure (ICP) control (Mohan et al. Acta Neurochir (Wien) 163(5):1415-1422, 2021), although the optimal technique remains controversial, particularly in the context of traumatic brain injury where recent landmark trials have evaluated decompressive craniectomy outcomes (Patel et al. Trauma Surg Acute Care Open 10: e001784, 2025). The bone flap is loosely secured to the cranium using surgeon's knots and adjustable slip knots, with slip knot suture ends exteriorized through the scalp. Once elevated ICP resolves, the bone flap is definitively secured by tightening the externalized sutures. This straightforward floating craniotomy technique provides controlled decompression, effective ICP management, and preserved cosmesis.

Microvascular procedures demand exceptional precision and are prone to technical errors that compromise outcomes. Performance improves fastest when errors are identified, measured, and corrected early during training. Error-based learning has become an essential part of microsurgical training, highlighting the importance of identifying and learning from mistakes to improve performance. This review aimed to systematically search the literature on all microsurgical errors and categorize them by operative phases. A structured literature search was conducted across Medline, Embase, and Web of Science databases, following PRISMA guidelines. Two reviewers independently screened records and extracted data in duplicate. Articles were included if they evaluated microvascular anastomoses with vessels less than 2 mm in diameter, and if microsurgical errors were detailed along with their impact on outcomes, in particular on anastomotic patency. Given the heterogeneity of the data, a SWiM-style (Synthesis Without Meta-analysis) narrative synthesis was used. A total of 34 studies met the inclusion criteria. Errors were categorized as pre-operative, intra-operative, and post-operative. Intra-operative errors were the most frequently reported. Back-wall stitches, uneven lumens, and excessive suture tension were consistently associated with reduced patency. Several validated scoring tools (e.g., ALI, MARS10, OSATS) were identified as effective in quantifying errors and guiding feedback in training settings. Microvascular anastomosis errors span all phases of the microsurgical procedure and significantly affect anastomotic success. This review offers a structured taxonomy of errors and underscores the importance of error-based learning and assessment in microsurgical training. Standardized error classification may enhance training programs, accelerating the acquisition of microsurgical skills along the learning curve and improving clinical outcomes.

Epilepsy surgery is the treatment of choice for drug-resistant epilepsy associated with hippocampal sclerosis. Patients over 50years of age have an increased risk of postoperative complications after epilepsy surgery. The authors present an operative video demonstrating right temporal lobe disconnection in a case of hippocampal sclerosis, along with an anatomical introduction and a section providing strategies to minimize complications. In selected cases, temporal lobe disconnection represents a viable alternative to resective procedures.

Digital 3D exoscopes have been introduced as alternatives for operating microscopes in microneurosurgery. It has been hypothesized that exoscope may provide benefits especially at the most anterior skull base, where surgical trajectories often require heavy tilting of the magnification device. We evaluated the safety and practicality of the digital 3D exoscopes in surgery of olfactory groove meningiomas (OGM) during the transition from using a microscope to an exoscope. In this retrospective cohort study, we included all consecutive adult patients who underwent surgery for OGM (n = 22) by a single senior neurosurgeon between 2016 and 2024 either with a microscope (n = 13) or an exoscope (n = 9). We reviewed the pre- and postoperative MRIs, patient records (including Modified Rankin Scale (mRS)), and surgical videos of all the patients. The surgical approach was unilateral fronto-temporal in all the cases. The patients in the exoscope group had larger tumors (median 61cm3 (IQR 49) vs. 17cm3 (IQR 32)), more clinical symptoms and required more help in their daily activities preoperatively (mRS ≥ 3: n = 3 (33%) vs n = 1 (8%)). Gross-total or near total resection was achieved in all the patients. The exoscopic surgeries took longer (165min (IQR 106) vs. 121min (IQR 27)), probably due to the larger tumor sizes. Two severe complications occurred, one in each group (post-op hematoma and blindness of ipsilateral eye). Clinical outcomes were nearly the same in both groups. At the 3-month follow-up, eight (89%, exoscope) and 12 (92%, microscope) patients were independent (mRS 0-2). Horizontal adjustments were more common when operating with the microscope (median 251 (range 148-359) vs. 103 (range 19-187)) while tilting movements were more frequent with the exoscope (median 122 (range 74-182) vs. 76 (range 44-133)). The surgical outcomes for OGMs remained consistent during the transition from using a microscope to an exoscope. The exoscope is a safe tool in the surgery of OGMs, even when operating on large tumors. The wider range of angular movement of the camera head is particularly advantageous when accessing the anterior skull base. In line with this, exoscope-assisted surgeries relied more on tilting movements, whereas microscope-assisted surgeries required more horizontal adjustment.